Some Physics questions! Please help!


1) 260 km/h
Let's use the following convention:
positive x-direction = east
positive y-direction = north
Here we have to find the north component of the velocity's airplane, which means we have to find its y-component.
We can use the formula:
[tex]v_y = v sin \theta[/tex]
where
v = 750 km/h is the magnitude of the plane's velocity
[tex]\theta=20.0^{\circ}[/tex] is the angle between the direction of the plane and the positive x-axis
Substituting,
[tex]v_y = (750)(sin 20)=256.5 km/h \sim 260 km/h[/tex]
2) [tex]24^{\circ}[/tex] north of east
In order to find the direction of flight, we have to consider that the vector representing the displacement of the plane is the hypothenuse of a right triangle, of which the displacements along the east and north direction are the sides.
Therefore, we have
[tex]v_x = 220 km[/tex] is the displacement towards east
[tex]v_y = 100 km[/tex] is the displacement towards north
Therefore, the angle that gives the direction is given by
[tex]tan \theta = \frac{v_y}{v_x}[/tex]
And substituting,
[tex]\theta =tan^{-1}( \frac{100}{200})=24^{\circ}[/tex]
and this angle is measured north of east.